Urotensin-II (U-II) is a cysteine-linked cyclic peptide, which exerts potent effects on the cardiovascular, renal, pancreatic, and central nervous systems. Originally, this substance was isolated from the urophysis (a caudal neurosecretory organ) of the goby fish (Gillichthys mirabilis) as a 12-mer, AGTAD-cyclo(CFWKYC)-V (D. Pearson. J. E. Shively, B. R. Clark, I. I. Geschwind, M. Barkley, R. S, Nishioka, H. A. Bern, Proc. Nat. Acad. Sci. USA 1980, 77, 5021-5024), but it has now been identified in all classes of vertebrates. The composition of U-II ranges from 11 amino acids in humans to 14 amino acids in mice, always with a conserved cysteine-linked macrocycle, CFWKYC. Recently, the U-II receptor was identified (R. S. Ames, H. M. Sarau, J. K. Chambers, R. N. Willette, N. V. Aiyar, A. M. Romanic, C. S. Louden, J. J. Foley, C. F. Sauermelch, R. W. Coatney, Z. Ao, J. Disa, S. D. Holmes, J. M. Stadel, J. D. Martin, W.-S. Liu, G. I. Glover, S. Wilson, D. E. McNulty, C. E. Ellis, N. A. Elshourbagy, U. Shabon, J. J. Trill, D. W. P. Hay, E. H. Ohlstein, D. J. Bergsma, S. A. Douglas, Nature (London) 1999, 401, 282-286) as a G-protein-coupled receptor (GPCR) previously known as the GPR14 orphan receptor, (M. Tal, D. A. Ammar, M. Karpuj, V. Krizhanovsky, M. Naim, D. A. Thompson, Biochem. Biophys. Res. Commun. 1995, 209, 752-759; and A. Marchese, M. Heiber, T. Nguyen, H. H. Q. Heng, V. R. Saldivia, R. Cheng, P. M. Murphy, L.-C. Tsui, X. Shi, P. Gregor, S. R. George, B. F. O'Dowd, J. M. Docherty, Genomics 1995, 29, 335-344) which is expressed predominantly in cardiovascular tissues.
Goby U-II possesses powerful vasoconstrictor activity in fish, mammals, and humans (J. M. Conlon, K. Yano, D. Waugh, N. Hazon, J. Exp. Zool. 1996, 275, 226-238; F. Böhm, J. Pernow, Br. J. Pharmacol. 2002, 135, 25-27). Moreover, it appears to be the most potent vasoconstrictor known, (S. A. Douglas, E. H. Ohlstein, Trends Cardiovasc. Med. 2000, 10, 229-237) causing concentration-dependent contraction of isolated arterial rings of rats and humans with an EC50 value of less than 1 nM, which is ca. ten times more potent than endothelin-1. Recently, Kikkawa, H. and Kushida, H. in International Publication WO 2005/072226 disclosed the use of Urotensin-II antagonists for the prevention and/or treatment of inflammatory bowel diseases including, but not limited to, Crohn's disease, ulcerative colitis, and inflammatory colitis caused by bacteria, ischemia, radiation, drugs, or chemical substances.
Relative to the role of U-II in chronic vascular disease, this peptide was reported to induce hypertrophy in cardiomyocytes (Y. Zou, R. Nagai, T. Yamazaki, FEBS Letters 2001, 508, 57-60) and the proliferation of smooth muscle cells (T. Watanabe, R. Pakala, T. Katagiri, C. R. Benedict, Circulation 2001, 104, 16-18), which suggests an involvement in heart failure and atherosclerosis. In addition, U-II has been shown to increase peripheral vascular tone, a characteristic of chronic heart failure (M. Lim, S. Honisett, C. D. Sparkes, P. Komesaroff, A. Kompa, H. Krum, Circulation 2004, 109, 1212-1214). Recent results have shown increased U-II receptor levels observed in the atherosclerotic lesions of the human aorta (N. Bousette, L. Patel, S. A. Douglas, E. H. Ohlstein, A. Giaid, Atherosclerosis 2004, 176, 117-123).
Relative to healthy individuals, the expression of U-II-like immunoreactivity was 2-fold higher in the plasma of patients with renal dysfunction who were not on dialysis, and 3-fold higher in those on haemodialysis (K. Totsune, K. Takahashi, Z. Arihara, M. Sone, F. Satoh, S. Ito, Y. Kimura, H. Sasano, O. Murakami, Lancet 2001, 358, 810-811). Recently, Kinoshita, M. and Kushida, H. in International Publication WO 2005/034873 disclosed the use of Urotensin-II antagonists for reducing nephrotoxicity and diarrhea caused by anti-neoplastic agents.
U-II has been described as a potential mediator in diabetes. For instance, U-II was shown to inhibit the release of insulin in the perfused rat pancreas in response to increasing glucose levels (R. A. Silvestre, J. Rodríguez-Gallardo, E. M. Egido, J. Marco, Horm. Metab. Res. 2001, 33, 379-381). Elevated U-II levels were seen in patients with diabetis mellitus (K. Totsune, K. Takahashi, Z. Arihara, M. Sone, S. Ito, O. Murakami, Clin. Sci. 2003, 104, 1-5) even without renal failure. Haplotypes in the urotensin II gene and urotensin II receptor gene are reported to be associated with insulin resistance and impaired glucose tolerance (K. Ong, L. Wong, Y. Man, R. Leung, Y. Song, K. Lam, B. Cheung, Peptides, 2006, 27(7), 1659-1667).
A U-II antagonist may be useful for the treatment of pain, neurological and psychiatric conditions, migraine, neuromuscular deficit, anxiety disorders and cardiovascular disorders. ICV (intracerebroventricular) administration of U-II increases rearing, grooming, and motor activity suggesting a CNS stimulatory activity (J. Gartlon, F. Parker, D. C. Harrison, S. A. Douglas, T. E. Ashmeade, G. J. Riley, Z. A. Hughes, S. G. Taylor, R. P. Munton, J. J. Hagan, J. A. Hunter, D. N. C. Jones, Psychopharmacology 2001, 155, 426-433). U-II increases Fos expression in the cingulate cortex and periaqueductal grey brain regions important in cognitive, emotional, and motor responses; the perceptions of pain; and panic responses (J. E. Gartlon, T. Ashmeade, M. Duxon, J. J. Hagan, D. N. C. Jones, Eur. J. of Pharmacol. 2004, 493, 95-98). U-II induces anxiogenic-like responses in rodents in the elevated plus maze and hole-board tests (Y. Matsumoto, M. Abe, T. Watanabe, Y. Adachi, T. Yano, H. Takahashi, T. Sugo, M. Mori, C. Kitada, T. Kurokawa, M. Fujino, Neuroscience Letters 2004, 358, 99-102).
Application JP 07242662 (also referred to as JP1995242662) describes substituted 4H-benzo[1,4]oxazin-3-ones as phospholipase A2 and interleukin 1 inhibitors.
PCT Application WO 03/091248 describes 7-fluoro-6-{1-[2-(7-fluoro-2-methyl-quinolin-5-yloxy)-ethyl]-piperidin-4-ylmethyl}-4H-benzo[1,4]oxazin-3-one as a 5-HT1A receptor inhibitor.
PCT Application WO 05/061457 describes substituted benzo[1,4]oxazines as renin inhibitors.
Accordingly, it is an object of the present invention to provide compounds that are Urotensin-II antagonists useful for treating Urotensin-II mediated disorders.
It is another object of the invention to provide a process for preparing compounds, compositions, intermediates and derivatives thereof.
It is a further object of the invention to provide methods for treating Urotensin-II mediated cardiovascular, renal, pancreatic and central nervous system disorders including, but not limited to, chronic vascular disease, vascular hypertension, heart failure, atherosclerosis, inflammatory bowel disease, Crohn's disease, ulcerative colitis, inflammatory colitis (caused by bacteria, ischemia, radiation, drugs or chemical substances), renal dysfunction, renal failure, renal failure caused by drug induced toxicity, nephrotoxicity and diarrhea caused by anti-neoplastic agents, nephrotoxicity caused by radiocontrast agents and aminoglycosides, post-myocardial infarction, pulmonary hypertension, pulmonary fibrosis, insulin resistance and impaired glucose tolerance, diabetes, diabetic complications, diabetic nephropathy, pain, Alzheimer's disease, convulsions, depression, migraine, psychosis, anxiety, neuromuscular deficit and stroke.